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Commit 4e40112c authored by Stefani Seibold's avatar Stefani Seibold Committed by H. Peter Anvin
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x86, vdso32: handle 32 bit vDSO larger one page 



This patch enables 32 bit vDSO which are larger than a page.

Signed-off-by: default avatarStefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-14-git-send-email-stefani@seibold.net


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 008cc907

arch/x86/vdso/vdso32-setup.c

+15 −7
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/mm.h>

#include <linux/err.h>

#include <linux/module.h>

#include <linux/slab.h>



#include <asm/cpufeature.h>

#include <asm/msr.h>
@@ -69,7 +70,8 @@ __setup_param("vdso=", vdso32_setup, vdso_setup, 0); 
EXPORT_SYMBOL_GPL(vdso_enabled);

#endif



static struct page *vdso32_pages[1];

static struct page **vdso32_pages;

static unsigned int vdso32_size;



#ifdef CONFIG_X86_64
@@ -115,11 +117,10 @@ void enable_sep_cpu(void) 


int __init sysenter_setup(void)

{

	void *vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);

	void *vdso_pages;

	const void *vdso;

	size_t vdso_len;



	vdso32_pages[0] = virt_to_page(vdso_page);

	unsigned int i;



	if (vdso32_syscall()) {

		vdso = &vdso32_syscall_start;
@@ -132,8 +133,15 @@ int __init sysenter_setup(void) 
		vdso_len = &vdso32_int80_end - &vdso32_int80_start;

	}



	memcpy(vdso_page, vdso, vdso_len);

	patch_vdso32(vdso_page, vdso_len);

	vdso32_size = (vdso_len + PAGE_SIZE - 1) / PAGE_SIZE;

	vdso32_pages = kmalloc(sizeof(*vdso32_pages) * vdso32_size, GFP_ATOMIC);

	vdso_pages = kmalloc(VDSO_OFFSET(vdso32_size), GFP_ATOMIC);



	for(i = 0; i != vdso32_size; ++i)

		vdso32_pages[i] = virt_to_page(vdso_pages + VDSO_OFFSET(i));



	memcpy(vdso_pages, vdso, vdso_len);

	patch_vdso32(vdso_pages, vdso_len);



	return 0;

}
@@ -169,7 +177,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
	 */

	ret = install_special_mapping(mm,

			addr,

			VDSO_OFFSET(VDSO_PAGES - VDSO_PREV_PAGES),

			VDSO_OFFSET(vdso32_size),

			VM_READ|VM_EXEC|

			VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,

			vdso32_pages);